Such a mobile communication network is already known in the art, e.g. from the pan-European digital cellular GSM network.
In this known network the terminals can be both hand-held and vehicle-operated. Whereas high speed vehicle-operated terminals require large cell sizes to reduce the number of hand-overs between cells, hand-held terminals necessitate small cell sizes as they inherently cover only a relatively small area due to their relatively low power consumption. Therefore the network infrastructure comprises two cellular structures each adapted to a specific environment: a first one with large cell sizes or macro-cells e.g. around rural areas in which only vehicle-operated terminals need to be supported and a second one with small cell sizes or micro-cells e.g. for pedestrian areas.
In the first structure the radio access links are used to directly access the base stations, known as base station controllers, one of which is provided in each macro-cell. These controllers are relatively complex as they have to provide the mobility control, including the hand-over decisions, and the routing to the fixed network. In the second structure such a solution would lead to a commercial drawback since providing such a complex base station in each micro-cell would require huge investments. Therefore, in the micro-cells, use is made of relay stations, called base transceiver stations, which have a minimum intelligence in the micro-cells and the traffic of a number of which, for instance corresponding to a macro-cell, is concentrated in a base station.
In this known mobile network the relay links are so designed that their influence on the ever-all communication path from a mobile terminal to the fixed network is negligible, so that only characteristics of the radio access link, which are variable due to the roaming behaviour of the mobile terminals, have to be considered.
The above network can however not be used for other environments than those for which it is expressly designed, i.e. high power vehicle-operated terminals in rural areas and low power hand-held terminals in pedestrian areas, since this would require an infrastructure other than the one described above. A further commercial drawback of the known infrastructure being the need for a separate network of relay links in order for these to be of the desired type with negligible influence on the over-all communication paths.